Lactocrine deficiency at birth alters the post natal day 14 porcine ovarian transcriptome

Authors: Wijesena, Hiruni; Miles, Jeremy; Oliver, William; BAGNELL, CAROL - Rutgers University; BARTOL, FRANK - Auburn University; Lents, Clay

Submitted to: Society for the Study of Reproduction Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/23/2026
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Lactocrine signaling refers to the postnatal transmission of milk-borne bioactive factors from mother to offspring, primarily through colostrum (first milk). This process is important for neonatal development with the potential for long-term consequences in adults. Colostrum intake in neonatal piglets can be quantified using the serum immunoglobulin immunocrit (iCrit) assay. Colostrum deficiency, indicated by low neonatal iCrit values, alters endometrial gene expression, delays uterine gland development in neonatal pigs, and increases age at puberty. Moreover, adult gilts that experienced neonatal lactocrine deficiency exhibit reduced litter size. Because litter size in pigs is influenced by both ovarian and uterine function, understanding the impact of lactocrine deficiency at birth on ovarian development is critical. The objective of this study was to characterize the ovarian transcriptomes of gilts with high (12.26% ± 0.71; n = 10) and low (1.95% ± 0.37; n = 12) iCrit values measured on postnatal day (PND) 1. High- and low- iCrit gilts were paired within litter. Ovaries were collected on PND 14, total RNA was extracted, and Illumina RNA sequencing was performed. A stringent bioinformatics pipeline was applied to identify and characterize both previously annotated transcripts in the Sscrofa 11.1 reference genome and novel transcripts expressed in the ovaries. A total of 54,525 expressed transcripts were identified, including 51,618 protein coding transcripts (30,858 annotated and 20,760 novel) and 2,907 noncoding transcripts (2,540 annotated and 367 novel). Transcript level differential expression analysis identified 724 transcripts that differed between high- and low- iCrit gilts at FDR-adjusted P-value = 0.05. Of these, 322 were previously annotated, while 398 were novel protein coding transcripts, and four were novel noncoding transcripts. The expressed transcripts corresponded to 17,862 genes. To obtain gene level expression data, the raw transcript P-values were aggregated for each gene locus. Sixty differentially expressed genes were identified at FDR-adjusted P-value = 0.05, including 57 previously annotated genes and three novel genes. Among these, 46 genes were more highly expressed in low iCrit gilts, whereas 14 were more highly expressed in high iCrit gilts. Genes highly expressed in low iCrit gilts included those involved in oxidative stress responses (GPX6, CYBA, SPATA18) and immune regulation (RFX1, TRIM29). Because colostrum is rich in antioxidants that help neonatal piglets adapt from the intrauterine to extrauterine environment, the elevated expression of these genes may reflect a compensatory ovarian response to putative oxidative stress in gilts that experienced lactocrine deficiency at PND 1. Additionally, lactocrine-deficient gilts exhibited increased expression of LHB, involved in gonadotropin synthesis and PLA2G6, involved in prostaglandin synthesis, suggesting altered endocrine signaling within the ovary. Collectively, these findings indicate that lactocrine deficiency on the first day of postnatal life alters porcine ovarian gene expression at PND 14, potentially contributing to disrupted ovarian development and reduced reproductive performance in adulthood. USDA is an equal opportunity provider and employer.